Fuel control system for injection type internal-combustion engines



May 9, 1950 M. MALLORY v FUEL CONTROL-SYSTEM FOR INJECTION TYPE INTERNAL-COMBUSTION ENGINES Filed Oct. 22, 1947 VACUI) INVENTOR. Maria/7 Mafia/y A TTQRNEYS Patented May 9, 1950 UNITED STATES PATENT OFFICE FUEL CONTROL SYSTEM FOR INJECTION TYPE INTERNAL-COMBUSTION ENGINES Marlon Mallory, Detroit, Mich.

Application October 22, 1947, Serial No. 781,466

7 Claims. (Cl. 123-103) This invention relates to a fuel control system for an injection type internal combustion engine.

This invention contemplates a fuel control system for an internal combustion engine of the injection type which is of simple structure and which will effectively and completely shut ofi the supply of fuel to the engine when the engine is being decelerated and the throttle closed, as, for example, in an automotive vehicle when the vehicle is driving or cverrunning the engine. Under such operating conditions my device will completely shut off the fuel and thereby prevent waste of fuel and the emission of smoke from the engine exhaust ports.

Fig. 1 is an illustrative showing of my fuel control system which is operated by vacuum.

Fig. 2 is an illustrative showing of my fuel control system which is operated by fluid pressure.

My control system can be used with either a low pressure injection engine or a Diesel high pressure injection engine. Injection pumps for injecting liquid fuel into low pressure injection engines or Diesel high pressure injection engines are old and well known. Such an injection pump is shown diagrammatically at (1. Such a pump has a shaft 2 which is driven by the engine and this shaft has'cams on the inside of the pump housing i which operate plungers that force the fuel out through fuel lines 3 to the engine cylinders. These pumps also have a reciprocable rod i known as'a throttle rack which controls orifices v to increase or reduce the fuel being forced intothe engine through fuel lines 3. In some of these pumps the throttle rack or rod varies the stroke of the plungers to vary the rate of injection oi. the fuel and in others of these pumps the throttie rack varies the size of the outlet orifices of the pumps. However, since injection pumps with throttle rods for metering the fuel being injected by the pumps are old and well known, and since the injection pump per se forms no part of my invention, it is believed that it is unnecessary to further describe the injection pump.

The various parts forming my fuel control system are referenced as follows: compression spring 5 positioned over throttle rod t acts between housing l and shoulder 8 on rod 4 and tends to move rod 4 toward the left, lever I pivoted on fixed support 8 as at 9 having one end In in contact with shoulder 6 and the other end ll pivotally connected to rod l2, tension spring l3 having one end anchored on stationary support H as at I! and the other end anchored as at it to bracket I! fixed on rod l2, vacuum pump "which is I! 2 preferably driven off the engine and the suction side of which is connected by conduit l9 with air bleed port 20 to atmosphere and by branch conduit 2| with servo-motor 22.

Servo-motor 22 comprises a, suction chamber 24, a flexible diaphragm 23 connected to one end of rod 26, a compression spring 25, the other end of rod 26 is pivotally connected as at 21 to cam lever 28 which is pivoted on support 8 as at 29. The cam is designated 30 and bears against lever 1. Air bleed portZll in valve housing 3| is controlled by a sliding valve 32 pivotally connected as at 33 to bracket 34 fixed on rod l2.

'Valve 32 closes port 20 when the control rod I2 is in engine idling position and opens port 20 whenever rod I 2 is moved toward the right to increase the rate of fuel injection to the engine. Engine driven shaft 2 has mounted thereon valve housing which rotates therewith. Shaft 2 is journalled in bea ing 36. Valve housing 35 has port 31 which communicates with atmosphere through port 38. Valve 39, fixed on piston 46, is reciprocably mounted in housing 35 and controls port 31. Tension spring M is connected at one end to valve 48 and at the other end to screw adjustment 42 for adjusting the tension of the spring. Spring 4| tends at all times to open valve 39, dd. H'ston so is provided with a longitudinally extending groove '33. Port 31 communicates through groove 53 and passageway 4 with branch conduit t5 connected into conduit i9.

Operation: If control rod i2 is moved toward the left so that lever i abuts cam to as at 50, Fig. 1, the control rod i2 and lever i will be in engine idling position and valve 32 will close air bleed port 26' to atmosphere. The tension of spring ti will be adjusted through adjustment 52 so that centrifugal valve 39 will close port 37 at engine speeds above approximately idle speed. say, for example, 500 or 600 R. P. M. While the engine is running at speeds above idle. centrifugal valve 39 will hold air bleed port 3? closed. Ii control rod i2 is in idle position and the engine is running or decelerating above idle speed, vacuum pump it, through lines it and it will build up a vacuum in suction chamber 2d of servomotor 22, thereby causing flexible diaphragm 23 to move'rod 26 downwardly and swing lever 28 counterclockwise so that the short radius of cam 30 now contacts lever l which permits tension spring l3 (which exerts a greater pull than the thrust of spring 5) to shift control rod l2 further toward the left from the position shown in Fig. 1, thereby swinging lever I counterclockwise causing end I II to push throttle rack 4 toward the right thereby completely shutting oi! the flow oi fuel from injection pump I to lines 3.

When the engine reaches a speed near its idle speed, piston valve 29, 40 will open bleeding air through port 31, passageway 43, conduits 44, 45 and I9 to suction chamber 24, thereby bleeding down the vacuum or raising the pressure in chamber 24 which causes spring 25 to raise rod 25, swing lever 28 clockwise so that high point 50 of cam 3|! again contacts lever 1 and swings lever 1 to idle position so that spring 5 now shifts throttle rack 4 toward the left to idle position (Fig. 1) so that the injection pump I now feeds sufllcient fuel through lines 3 to the engine cylinders for idle operation. This completely shutting off the fuel is particularly important when the engine is driving an automotive vehicle and the vehicle is overrunning the engine. Such condition obtains, for example, while the vehicle is being brought to a stop from a speed greater than idle with the throttle in idle position.

If at any time while decelerating, control rod 12 is moved to the right of idle position, valve 32 will open port 20 to atmosphere thereby immediately bleeding down the vacuum in servomotor 22 and restoring lever 28 to idle position. In other words, my degasser arrangement cannot operate to completely shut off the fuel when control rod I2 is not in idle position because at this time air bleed port to atmosphere will be open and the pressure in chamber 24 will be substantially atmospheric.

In the form of my fuel control system shown in Fig. 2, the operation is identical with the system shown in Fig. 1 except that fluid pressure is utilized for operating the servo-motors instead of vacuum. In this form of the invention I have shown an oil sump 5|, 9. liquid pump 52, the suction side of which is connected by conduit 53 with sump 5| and the high pressure side of which is connected by conduit 54, 55, 55 with pressure chamber 51 of servo-motor 22. Chamber 58 is provided with a breather port 59 to atmosphere. Pressure line 55 is connected with the interior of stationary housing 60. Passageway 6| is connected by conduit 62 with sump 5|. "iranch line 63 connects into conduit 55 and into fluid bleed port 64 which is controlled by valve 32. The fluid bleeding out of-port 54 returns through line 55 to sump 5i. a

The principle of operation of this form of the invention is the same as that of the principal form. Pump 52 is preferably driven oi the engine. As shown in Fig. 2, the various parts are in engine idling position. If control rod I2 is in idle position, Fig. 2, and the engine decelerates or the vehicle which the engine is driving overruns the engine, then valve 39 will remain closed until the engine approaches idle speed, say, in the neighborhood of 500 or 600 R. P. M. With valve 39 closed, all under pressure will pass through conduits 54, 55, 56 to pressure chamber 51 thereby swinging cam lever 30 counterclockwise to press the shorter radius of cam 30 against lever 1 thereby permitting spring l3 to swing lever 1 counterclockwise which moves throttle rack 4 to the right completely shutting off the injection of fuel to the engine. As in the principal form of the invention, oil bleed port 64 will be closed by valve 32 when rod 12 is in idle posi--, tion. When the engine decelerates to approxi-;

mately idle speed, valve 39 opens port 31 thereby bypassing the oil through groove 43, passageway 6| and conduit 82 back to sump 5| thereby relieving the pressure in chamber 51 and permit- 4 ting spring 25 to move lever 28 clockwise back to idle position, Fig. 2, whereupon spring 5 moves throttle rack 4 to idle position.

In both forms of the invention it will be seen that the servo-motor 0r suction device 22 is cperated by fluid pressure and responds to a change in fluid pressure to swing cam lever 28. In the form shown in Fig. l the pressure above diaphragm 23 is always atmospheric and the pressure below diaphragm 23 in suction chamber 24 is atmospheric pressure when either or both ports 20 and 31 are open and when both these ports are closed the pressure in chamber 24 will be sub-atmospheric. Similarly in the form shown in Fig. 2, the pressure on the underside of diaphragm 23 will always be atmospheric and the pressure in chamber 51 will be greater than atmospheric whenever ports 64 and 31 are closed. In each case the flexible diaphragm shifts its position whenever the pressure in the variable pressure chamber changes whether the pressure be liquid pressure greater than atmospheric or air pressure less than atmospheric.

I claim:

1. In an internal combustion engine of the injection type including means for throttling the flow of fuel into said engine, a second means tending to move said throttling means toward fully closed position to completely shut oif the injection of fuel into said engine, a stop co-acting with the second means whereby the second means is normally effective to bring said throttle means only to idle position, a servo-motor actuated by changes in fluid pressure and connected to said stop, a fluid bleed port for said servo-motor, a valve actuated in accordance with the speed of the engine for holding said fluid bleed port closed at engine speeds greater than idle speed, a second fluid bleed port for said servo-motor, and a valve for said second fluid bleed port which is closed when said throttle means is in idle position and which is open when the throttle means is open wider than idle position whereby when the engine is running at speeds greater than idle speed with the throttle means at idle position then said servo-motor will actuate said throttle means to fully closed position to thereby shut ofi all fuel to the engine.

2. In an internal combustion engine of the in- ,iection type including means for throttling the flow of fuel into said engine, resilient means tending to move said throttling means toward fully closed position to completely shut oil the injection of fuel into said engine, a stop co-acting with the resilient means whereby the resilient means is normally effective to bring said throttle means only to idle position, a servo-motor actuated by changes in fluid pressure and connected to said stop, a fluid bleed port for said servo-motor, a valve actuated in accordance with the speed of the engine for holding said fluid bleed port closed at engine speeds greater than idle speed, a second fluid bleed port for said servo-motor, and a valve for said second fluid bleed port, a connection between said last mentioned valve and said throttling means whereby said last mentioned valve is closed when the throttle means is in idle position and is open when the throttle means is open wider than idle position whereby when the engine is running at speeds greater than idle speed with the throttle means at idle position then said servo-motor will actuate said throttle means to fully closed position to thereby shut off all fuel to the engine.

tion of fuel into said engine, a stop co-acting with said means whereby said means is normally effective to bring said throttle rod only to idle position, a servo-motor actuated by changes in fluid pressure and connected to said stop, a fluid bleed port for said servo-motor, a valve actuated in accordance with the speed of the engine for holding said fluid bleed port closed at engine speeds greater than idle speed, a second fluid bleed port for said servo-motor, and a valve for said second fluid bleed port which is closed when said throttle rod is in idle position and which is open when the throttle means is open wider than idle position whereby when the engine is running at speeds greater than idle speed with the throttle rod at idle position then said servo-motor will actuate said throttle rod to fully closed position to thereby shut oif all fuel to the engine.

4. In an internal combustion engine of the injection type including a throttle rod for throttling the flow of fuel into said engine, resilient means tending to move said throttle rod toward fully closed position to completelyshut off the injection of fuel into said engine, a stop co-acting with said means whereby said means is normally effective to bring said throttle rod only to idle position, a servo-motor actuated by changes in fluid pressure and connected to said stop, a fluid bleed port for said servo-motor, a centrifugally unbalanced valve actuated in accordance with the speed of the engine for holding said fluid bleed port closed. at engine speeds greater than idle speed, a second fluid bleed port for said servomotor, and a valve for' said second fluid bleed port which is closed when said throttle rod is in idle position and which is open when the throttle means is open wider than idle position whereby when the engine is running at speeds greater than idle speed with the throttle rod at idle position then said servo-motor will actuate said throttle rod to fully closed position to thereby shut off all fuel to the engine.

5. In an internal combustion engine of the injection type including a throttle rod for throttling the flow of fuel into said engine, resilient means tending to move said throttle rod toward fully closed position to completely shut off the injection of fuel into saidengine, a shiftable stop co-acting with said throttle rod in opposition to said resilient means, said stop in the one position opposing said resilient means so that the resilient means is eflective to bring said throttle valve only to idle position, said resilient means when the stop is in the other position moving said throttle rod to fully closed position, a servo-motor actuated by changes in fluid pressure and connected to said stop, a fluid bleed port for said servo-motor, a valve actuated in accordance with the speed of the engine for holding said fluid bleed port closed at engine speeds greater than idle speed, a second fluid bleed port for said servo-motor, and a valve for said second fluid bleed port which is closed when said throttle rod is in idle position and which is open when the throttle means is open wider than idle position whereby when the engine is running at speeds greater than idle speed with the throttle rod at idle position then said servo-motor will actuate said throttle rod to fully closed position to thereby shut off all fuel to the'engine.

6. In an internal combustion engine of the injection type including a throttle rod for throttling the flow of fuel into said engine, resilient means tending to move said throttle rod toward fully closed position to completely shut oil the injection of fuel into said engine, a shiftable stop co-acting with said throttle rod in opposition to I said resilient means, said stop in the one position opposing said resilient means so that the resilient means is effective to bring said throttle valve only to idle position, said resilient means when the stop is in the other position moving said throttle rod to fully closed position, a servomotor actuated by changes in fluid pressure and connected to said stop, a fluid bleed port for said servo-motor, a centrifugally unbalanced valve actuated in accordance with the speed of the engine for holding said fluid-bleed port closed at engine speeds greater than idle speed, a second fluid bleed port for said servo-motor, and a valve for said second fluid bleed port which is closed when said throttle rod is in idle position and which is open when the throttle means is open wider than idle position whereby when the engine is running at speeds greater than idle speed with the throttle rod at idle position then said servo-motor will actuate said throttle rod to fully closed position to thereby shut oif .all fuel to the engine.

'7. In an internal combustion engine of the injection type including a throttle rod for throttling the flow of fuel into said engine, a control member for saidthrottle rod, resilient means acting on said control member whereby the control member tends to move said throttle rod toward fully closed position to completely shut oil the injection of fuel into the engine, a shiftable stop against which said control member abuts when in idle position, a servo-motor actuated by changes in fluid pressure and connected to said stop, a fluid bleed port for said motor, avalve actuated in accordance with the speed of the engine for holding said fluid bleed port closed at engine speeds greater than idle speed, a second'fluid bleed port for said servo-motor, and a valve for said second fluid bleed port, a connection between said last mentioned valve and said control member whereby the last mentioned valve closes said second fluid bleed port when said control member is in idle position and is open when the throttle means is open wider than idle position whereby when the engine is running at speeds greater than idle speed with the control member at idle position then said servo-motor. will respond to a change in fluid pressure and move said stop away from said throttle member and the resilient means will act through said control member to move said throttle rod to fully closed position.

MARION MAILORY.

, REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,323,997 Hughes July 13, 1943 2,361,103 Issigonis Oct. 24, 1944 

